The article's full title:
The benefits of hindsight....The need for more monitoring of domestic terrorism
Noted via Twitter today, it appeared on the 18th August, starting with this 2009 DHS report and ends pithily:
..talking about right-wing extremist threatens howls of protest. Nice idea, shame about the politics.
Link:http://www.economist.com/node/215605...s_of_hindsight

The comments illustrate the difficulty in this area of public safety policy and in IMHO are not worth reading in total.